Why is ACLU involved in driver suspension case?

Why is the ACLU getting involved in a case like Reginald Foster's? I thought the ACLU was an organization for rights in this country. Driving is a privilege, not a right. Mr. Foster has five felony convictions against him. In the past days, we have seen what irresponsible drivers can do to change the lives of innocent, law-abiding people and law enforcement.

Why doesn't the ACLU devote its time to things that it should stand for, rather than try to get media coverage?